HOSE AS 2655655 - Caterpillar

Probable Causes
Diagnostic codes, event codes, and the power supply for the Electronic Control Module (ECM)
Air inlet heater
Engine shutdown switches
Engine speed/timing
Injection actuation pressure
Unit injectors
Fuel supply
CombustionRecommended Actions
Diagnostic Codes, Event Codes, and ECM Power Supply
Certain diagnostic codes and/or event codes may prevent the engine from starting. Connect the Caterpillar Electronic Technician (ET) and check for active codes and/or for logged codes. Troubleshoot any codes that are present before continuing with this procedure.Note: If Cat ET will not communicate with the ECM, the problem is most likely with the electrical power supply to the ECM. Refer to Troubleshooting, "Electrical Power Supply Circuit - Test".Air Inlet Heater
Ensure that the air inlet heater is working properly. Ensure that the heater element is in good repair. For additional information on the air inlet heater, refer to Troubleshooting, "Air Inlet Heater Circuit - Test".Engine Shutdown Switches
The engine shutdown switches should be in the RUN position. Use Cat ET to verify the status of the shutdown switches. When a shutdown occurs, the shutdown switch must be reset prior to restarting the engine. On some applications, the keyswitch must be cycled before the ECM will allow engine cranking. Allow the keyswitch power to the ECM to be in the OFF position for at least 15 seconds prior to restarting the engine.Note: If Cat ET will not communicate with the ECM, the problem is most likely with the electrical power supply to the ECM. Refer to Troubleshooting, "Electrical Power Supply Circuit - Test".Engine Speed/Timing
Crank the engine and observe the engine speed on the Cat ET status screen. If Cat ET indicates zero rpm, refer to Troubleshooting, "Engine Speed/Timing Sensor Circuit - Test". Note: Upon initial cranking, the status for engine speed may indicate that the engine speed signal is abnormal. This message will be replaced with an engine speed once the ECM is able to calculate a speed from the signal.
Ensure that the timing reference gear is installed correctly. The engine will not start if the gear was installed backward. Check for proper orientation between the crankshaft and camshaft drive gears. Correct the orientation and/or replace the drive gear, if necessary. Refer to the Disassembly and Assembly for information that relates to the correct installation of the front gear train. Injection Actuation Pressure
Check the engine oil level. Engine oil supplies the injection actuation pressure circuit. The engine oil must be kept at the proper level for fuel injection.
If service has recently been performed on the engine, air may be present in the injection actuation pressure circuit. Allow the engine to fully warm up and operate the engine under load in order to purge the air from the injection actuation pressure circuit.
Check the injection actuation pressure. Refer to Troubleshooting, "Injection Actuation Pressure - Test" for the correct procedure.
Check the operation of the injection actuation pressure control valve. Refer to Troubleshooting, "Injection Actuation Pressure Control Valve Circuit - Test" for the proper troubleshooting procedure. Unit Injectors
Perform the "Injector Solenoid Test" on Cat ET in order to determine if each of the